What does bacterial infection mean. Signs of a viral infection in a blood test. Symptoms of an attack by pathogenic bacteria

But maybe someone will come in handy, so open post. Thanks for the post to one mom-paramedic from the Country of Moms.

First things first.

Second.

What is the analysis. General blood test (CBC). This is the easiest way to determine what type of infection. The doctor will see for himself, but if briefly, then with a virus, leukocytes are normal / slightly higher / slightly lower. According to the leukocyte formula, the virus is given out by lymphocytes, monocytes - their increased value. But neutrophils are low.
With a bacterial infection, leukocytes are immediately and markedly increased. And, unlike the virus, neutrophils too (but lymphocytes are lowered).

Disclaimer: this is all for acute diseases. In chronic cases, the picture may be different.

If a fever persists for a long time (more than 3 days) - this is also a sign of a complication of a viral infection with a bacterial component.

And third. For dessert. How to treat this annoying virus?
But no way. Why treat him - he is healthy Joke. Treatment is symptomatic. That is, we cannot treat the virus - we treat what prevents it from functioning. We remove snot, relieve cough, get rid of intoxication.

The drink is plentiful. Compotes, fruit drinks. Many neglect this, they say, what is there - drinking, treatment or something. And yes. A lot of water - intoxication is "diluted" and excreted by the kidneys, conditionally. Also good, sufficient drink dilutes phlegm. For those who like to pour mineral water into a nebulizer, it is best to pour it inside - the action is much better and certainly without negative consequences.

Further. Air humidification. A humidifier is fine, but if it is not there, then a wet towel on the radiator. If the temperature is below 38 and health is normal - walk. Especially if there is no wind. The main thing is not to let the child sweat and cool in the cold. And leisurely walks (in a stroller, in small steps) are very useful. True true

Yet. With an increase in temperature and normal health - do not bring down the temperature to 38 (if there are no febrile convulsions). It is at temperatures up to 38 degrees in the blood that lymphocytes begin to increase in number, which are responsible for cellular immunity, and, accordingly, for recovery and subsequent resistance to this virus.

Further. The inside of the nose should be moist. And this is air humidification (which I already wrote about) and irrigation of the nasal cavity. It doesn't matter which way. Either teach the child to rinse the nose from the palm of your hand (to draw in water), or with all these sprays like Aquaphor / Aquamaris. Or from a syringe with saline. The virus will not wash it away, but the development of green snot will completely prevent it.

And the gist: about infectiousness.
Infectious is a virus. And bacterial complications in acute respiratory infections are not contagious. It is technically impossible to infect with green snot, unless you smear them in your nose. The transparent discharge in large quantities contains colonies of viruses, which, when coughing and sneezing under pressure, disperse and catch their future carriers, settling on their mucous membranes (nose, mouth). It is also unrealistic to infect with a wet cough, because sputum is coughed up with the remnants of bacteria and their vital activity. And getting infected with them is like getting infected with cystitis or, say, heartburn.

All acute respiratory diseases - among the people of acute respiratory infections - are of a bacterial or viral nature. A viral infection, or SARS, is caused by several types of viruses, such as rhinovirus, adenovirus, parainfluenza, and influenza. Influenza is usually isolated from standard SARS, because its course is much more severe and complications are terrible.

So, what is their fundamental difference for parents?

First things first. Respiratory viral infection NOT TREATED with antibiotics. I am writing this for those who like to “serve amoksiklavchik and sumamedik as soon as 37.5 rises”

Brief excursion into microbiology and virology.
A virus is not a cell. This is the so-called extracellular form of life, which reproduces by introducing into the host cell and begins to synthesize its proteins.
A bacterium is a unicellular organism. Reproduces by division.

How an antibiotic acts on a bacterium: it prevents the reproduction of bacteria, or violates their shell and structure. Depending on this, there are antibiotics-bactericides - killing, and antibiotics-bacteriostatics - stopping growth and reproduction.
How does an antibiotic work on a virus?
Virus and bacteria are different sizes. The virus is thousands of times smaller than bacteria (this is the question of wearing a mask during epidemics)
Therefore, trying to treat a viral infection with an antibiotic is a disastrous and thankless task. Not only is there no benefit, but resistance (resistance and uselessness of use) to certain antibiotics is also developing.

Second. When and how to understand what type of infection a child has?

The onset of all ARIs is usually viral. This is a clear discharge from the nose, sneezing, dry tickling cough (rarely barking, not to be confused with laryngitis and false croup), the temperature is most often subfebrile (up to about 37.5-37.8), less often above 38, redness of the throat and pain during swallowing. With all this, the child has poor and poor health, that is, the temperature seems to be low, but the child is lethargic and capricious - this is the so-called infectious intoxication.

If ARI is bacterial, then the temperature is high and there are signs of fever by the hour. That is, at certain times of the day (after lunch, in the evening) the temperature is increased for several days. With all this, at a fairly high temperature, the child is alert, can jump, play, and so on. Bacterial complications of a viral infection most often occur in children or people with reduced immunity. If there was a cough at the beginning of the disease, then with bacterium. complication occurs and sputum is coughed up. If the discharge from the nose was transparent and whitish, then it becomes green, yellow. All these manifestations are clear and 100% symptoms that a bacterium has joined the virus.

So, what is their fundamental difference for parents?

First things first. Respiratory viral infection NOT TREATED with antibiotics. I am writing this for those who like to “serve amoksiklavchik and sumamedik as soon as 37.5 rises”

Second. When and how to understand what type of infection a child has?

Unfortunately, not many people know the differences between these concepts, which leads to improper treatment, and this threatens with serious and dangerous consequences. There is a huge difference between treatment and. We have previously published articles - and we also recommend reading them!

So what is the difference between a virus and an infection, then we will consider in detail!

A virus is a very simple form of life that is on the verge between organic and inorganic nature. In fact, this is genetic material, i.e. DNA (Deoxyribonucleic acid) and RNA (Ribonucleic acid) in a protein shell that serves as protection. Without host cells, the virus cannot reproduce. In addition, they do not have their own metabolism, which means they cannot eat.

How does the virus get infected?

At the first stage, the protective shell of the virus is attached to the membrane of another cell.

Most viruses can only attach to certain types of organisms. Infection occurs when a virus transfers its RNA and DNA (genetic material) into a second cell (the host cell). There it begins to rapidly develop using certain internal systems of the host cell. Creates protein particles.

After a sufficient number of particles have been created, new viruses are assembled from nucleic acids and produced proteins. And then, it destroys the host cell and is released. The released particle tends to infect a new cell. This process is repeated over and over again, each time destroying the host cells. This causes the progression of the disease and the release of viruses into the external environment, infecting new people or animals.

Unlike viruses, bacteria are full-fledged cells that have the necessary organelles for the synthesis of substances and energy production. These cells can multiply. The genetic material is contained in the cytoplasm, i.e. intracellular fluid. This is caused by the absence of a nucleus, which stores the genetic material in most types of cells.

How do bacterial diseases develop?

As mentioned earlier, bacteria are full-fledged cells capable of reproducing without the help of a host organism, most often this occurs by division. They have their own metabolism, and accordingly they can feed on their own. It is as food that bacteria usually use the host. The organism, where the bacteria have penetrated, is perceived by them as a comfortable environment for reproduction. In the course of their life activity, they damage the host cells and poison them with waste products (toxins). This leads to the development of the disease.

Treatment of viral and bacterial diseases differ significantly precisely because of their different nature.

Antibacterial drugs are aimed at the destruction of bacteria, as well as blocking the ability to reproduce.

Drugs against viruses

Antiviral drugs have three directions of action:

Stimulation of the defense mechanisms of the host organism itself to counteract viruses that have entered the body;
Violation of the structure of viral particles. Usually these drugs are analogues of nitrogenous bases. This substance acts as a material for the synthesis of nucleic acids, from which RNA and DNA are built. The modified substances are integrated into the genetic material of the virus, which leads to the deformation of the created viruses. Due to their own defect, these particles cannot multiply and create new particles;
Preventing the entry of the virus into the host cell. Thus, viral DNA and RNA cannot detach from the protective protein shell, and they cannot penetrate the cell membrane.

Encephalitis is caused by viruses, while borreliosis is caused by bacterial activity, which leads to different treatments for these diseases.

The drug Jodantipyrin acts in the third direction. It prevents the penetration of encephalitis into the cell protected by it.

If the virus has entered the body and infect it, then the drug blocks the further development of the disease. It is recommended to use this Yodantipyrin before visiting places where there is a threat of infection with encephalitis, i.e. habitats of ticks (forests, parks, meadows, etc.).

Immunoglobulin

Immunoglobulen is a rather specific drug that is aimed at neutralizing all types of bacteria and viruses. It produces its own and individual types of immunoglobulins in the body. This drug belongs to the category of immunobiological drugs. Do not use this remedy in emergency cases, as it can cause an acute allergic reaction and lead to very serious consequences. Before use, you need to consult with a specialist who will prescribe a specific regimen for taking the drug.

Immunoglobulen and Yodantipyrin are completely different drugs that have different protection mechanisms and tasks from each other. In emergency cases, Yodantipyrin should be taken, which blocks the disease at the initial stage, and Immunoglobulin excites the body to produce certain antibodies that can destroy encephalitis. The drugs have contraindications and you need to read the instructions, and in the case of Immunoglobulen, consult a doctor. More details about the effect of the drug and the results of clinical trials can be found in the specialized literature, in medical reference books.

Video: How to distinguish a viral disease from a bacterial one

The winter-spring period is the time of the year when various respiratory infectious diseases most often develop. The most common pathogens that cause these ailments are viruses and bacteria. Despite the fact that the clinical manifestations of these diseases may be similar, the treatment tactics for them are completely different. Viral diseases in most cases do not require special treatment, only symptomatic measures (reducing the temperature and viscosity of sputum, various drops in the nose and painkillers for the throat). But an infection caused by bacteria is an indication for a doctor to prescribe antibiotics. How to recognize the true cause of the infectious process?

Specialists of the Interregional Association for Clinical Microbiology and Antimicrobial Chemotherapy claim that various viruses are the cause of 98% of acute infections of the upper respiratory tract and bronchitis in adults. For children, this figure is somewhat lower, but, nevertheless, is also very high and amounts to 92-94%.

The vast majority of viral diseases undergo complete self-healing within 10-14 days. Of these, the first 7 days is the acute phase, during which there is fever and various respiratory symptoms, and the next 3-7 days is the recovery period. This means that the use of antiviral drugs does not play a decisive role in people, with the exception of people with severe immunosuppression (primary immunodeficiency, people taking corticosteroids, cytostatics, after radiation and chemotherapy, etc.).

Most common viral infections

Most often in the winter-spring period, the following types of viral infections occur:

Influenza virus. Severe intoxication, high fever, sometimes dry cough, sore throat and runny nose (the latter is not necessary).
Rhinovirus. Slight fever (maximum 38°C), runny nose, nasal congestion and sneezing predominate. Complications - otitis media and sinusitis.
parainfluenza virus. Slight fever (maximum 38°C), cough, sore throat. In children, it is dangerous for the development of laryngostenosis (false croup).
adenovirus. Febrile fever (up to 39 ° C), purulent discharge from the eyes, redness and pain in the eyes, cough. It has a two-wave course (on the 5th day, a rise in temperature is again observed).
RS virus infection. Slight fever (up to 38 ° C), cough with sputum. Children often develop bronchial obstruction (shortness of breath, wheezing in the chest).
Metapleumovirus infection. It is similar to the RS virus, but in addition, otitis media and rhinitis are possible. Dangerous for children under 2 years old, often gives a complication in the form of pneumonia.
Infectious mononucleosis. It is similar to bacterial tonsillitis. Severe intoxication and high fever (up to 40 ° C). Sore throat and greatly enlarged submandibular lymph nodes. Schoolchildren and students get sick more often, less often - preschoolers and adults.

All of these diseases proceed in different ways, but since most of them do not require special treatment (with the exception of the influenza virus), doctors rarely make a specific diagnosis. Usually it sounds like this: "ARVI", "acute nasopharyngitis", "acute laryngotracheitis".

Most often, respiratory infectious diseases are caused by those bacteria that are constantly on the body and are conditional pathogens. For some reason, the body's defenses are reduced, and these microorganisms penetrate the cells of the mucous membrane of the oral cavity, tonsils, pharynx, trachea, bronchi, nose, or inside the sinuses. The most common causes of such diseases are hemolytic streptococcus and pneumococcus, Staphylococcus aureus, Haemophilus influenzae and atypical pathogens (mycoplasma, respiratory chlamydophila and legionella).

They can cause various diseases: acute tonsillitis (tonsillitis), sinusitis (sinusitis, frontal sinusitis), laryngitis, tracheitis, bronchitis, otitis media, pneumonia, etc. However, the clinical manifestations of these ailments are similar to those caused by viruses and it is not so easy to distinguish them simply.

Difference between viral and bacterial infectious diseases

The problem of differentiation of viral and bacterial infections is extremely relevant today. And it is extremely difficult for a doctor in a polyclinic who is allocated only 12 minutes to communicate with a patient to do this in the allotted time. For this, various diagnostic methods are used:

Bacterial diseases are accompanied by high fever and the presence of purulent discharge (from the nose, on the surface of the tonsils, with sputum).
Bacterial diseases are characterized by the absence of positive dynamics on the 5-7th day (which most often occurs with viral infections) and the second wave of deterioration after a period of improvement (with the exception of adenoviruses).
Blood test: viral infections are characterized by an increase in the number of lymphocytes, bacterial - neutrophils. In both cases, the level of leukocytes and ESR increases.
Rapid test for streptococcus and influenza virus (not carried out everywhere).
Microscopic examination of nasal discharge, throat swab, sputum analysis.
Other tests: procalcitonin, C-reactive protein, the study of protein fractions. They are expensive and used as a last resort.

The difference between infections caused by bacteria and viral infections is that antibiotics are the main aspect in their treatment. Western experts give a certain percentage of patients (20-30%) for whom self-healing is possible from bacterial diseases, because the human immune system is very strong and can even fight them. However, the lack of antimicrobial treatment in this case is fraught with serious complications, up to such serious illnesses as pneumonia, meningitis, endocarditis and sepsis. Therefore, in the presence of effective antibiotics, the risk caused by the lack of treatment (in the hope of getting into these 20-30% of people) is unreasonably high.

Timely access to a doctor with a cold infection significantly reduces the risk of complications. Do not self-medicate, even with a banal SARS.

Knowing how to identify a viral or bacterial infection by a blood test, you can avoid mistakes in choosing medicines. This will not only make therapy effective, but also prevent negative consequences from the use of drugs such as antibiotics and sulfonamides.

A blood test will help in making a diagnosis.

To decipher the leukocyte formula, you need to know the content of blood cells in the norm, as well as the shifts that various microorganisms cause. Despite the existence of exceptions to the rules, there are general patterns in the change in its composition.

Changes in bacterial infection

During the reproduction of pathogenic bacteria occurs:

an increase in the number of leukocytes and neutrophils (in rare cases, they do not exceed the norm);
a slight decrease in the number of lymphocytes (sometimes normal);
increase in ESR.

The presence in the blood of immature forms of granulocytes, which include metamyelocytes and myelocytes, indicates a severe form of pathology.

Viral changes

It is possible to assume infection of the body with viruses if the picture of blood parameters during the analysis is as follows:

the number of leukocytes is slightly reduced or normal;
an increase in the number of lymphocytes and monocytes;
decrease in the number of neutrophils;
slight increase in ESR.

When infected with the hepatitis C, B or HIV virus, no changes in blood test parameters are observed, since the body does not perceive these microorganisms as a foreign protein, does not produce antigens and interferon. For an accurate diagnosis, reactions using specific markers are used.

Specific markers will show the nature of the disease

The shift of the leukocyte formula and the erythrocyte sedimentation rate can change during a protracted chronic infection, when organ cells are destroyed.

Exceptions to the rules

The penetration of tuberculosis and syphilis bacteria into the human body is accompanied by a slight increase in the number of lymphocytes and monocytes, which is typical for infections of viral etiology. This also happens with the development of fungal microflora.

A significant increase in ESR indicates the presence of malignant tumors, heart attacks, dysfunction of the endocrine glands, kidneys, liver, autoimmune diseases.

A strong increase or decrease in the level of leukocytes indicates leukemia or leukopenia. In this case, bacterial and viral infections do not play a role, since these pathologies can be caused by prolonged antiviral or chemotherapy, radiation exposure, and other factors.

Leukocyte formula

Before determining a viral or bacterial infection, one should understand the concept of "leukocyte formula", which in the medical literature is called a leukogram.

This term refers to the ratio of different forms of leukocytes in relation to each other, expressed as a percentage. It is determined by counting cells in a smear under a microscope.

A healthy person is characterized by the presence in the peripheral circulation of mature segmented neutrophils and a small number of young stab forms. The presence of immature granulocytes (metamyelocytes, myelocytes and promyelocytes), which should not normally be present, can show the development of severe pathologies. This happens when the number of microbes significantly exceeds the number of mature immune cells that do not have time to cope with disease-causing agents.

The detection of young leukocytes in smears and an increase in the number of stab forms is called the "shift of the leukocyte formula to the left."

A liter of blood of a healthy person contains 4.5-9 * 10⁹ leukocytes. Viral infections do not have a significant impact on this indicator, and the bacterial microflora increases it by 2-3 times.

Making a final diagnosis

A blood test is not the only indicator that is taken into account when making a diagnosis, since in medical practice there are cases when viral infections are complicated by the development of bacterial microflora. Against the background of a general decrease in the level of immunity, there is an increased reproduction of conditionally pathogenic microorganisms that cause the development of inflammation and pathologies. The doctor draws conclusions and prescribes treatment only after a complete clinical examination. Sometimes additional research is needed (radiography, cardiogram, biopsy, and others).

In the autumn-winter period, a person is prone to infections of the upper respiratory tract. Sometimes it is difficult to distinguish a bacterial infection from a viral one, which is very important in terms of the choice of therapy. Only bacterial infections require antibiotic treatment, and unrecognized and improperly treated, can lead to serious complications.

Bacterial and viral infection

It happens that during a viral infection there is a development bacterial superinfection. Therefore, bacterial and viral infections are not completely different diseases, they can coexist with each other, giving a varied clinical picture.

bacterial infection upper respiratory tract is characterized by symptoms in the form of high fever, plaque on the tonsils, redness and swelling of the mucous membranes of the nasopharynx. In the case of bacterial inflammation of the paranasal sinuses, nasal discharge is green/yellow.

Viral infections flow, as a rule, with a lower temperature, although this is not the rule. Infection, for example, with the Epstein-Barr virus, which causes infectious mononucleosis, leads to a significant increase in body temperature.

With bacterial infections, an increase in the anterior lymph nodes is more often noted, and with viral infections, the posterior cervical ones. With viral infections, more often than with bacterial ones, symptoms appear in the form of a runny nose, cough, pain in the muscles and joints.

You should also remember about nonspecific course of bacterial and viral infections, especially in children. They can only give symptoms in the form of pain in the abdomen or head.

How to distinguish a viral infection from a bacterial one

It is often possible to distinguish a bacterial infection from a viral one on the basis of a clinical examination. In addition, in a doubtful situation, the physician initiates empiric treatment in relation to the most likely diagnosis.

There are also laboratory methods used in differential diagnosis. In infection, a non-specific marker is C-reactive protein (CRP). It indicates that an inflammatory process is developing in the body, however, it does not specify what the etiology of inflammation is. For bacterial infection general blood test in a smear shows an increase in the percentage of neutrophils. In viral - lymphocytes predominate.

Another diagnostic method for differentiating bacterial and viral infections is smear from the site of infection. This allows not only to confirm a bacterial infection, but also to determine the etiological factor. However, if the symptoms indicate a viral infection, a pap smear is not performed. This is due to the fact that often people are carriers, for example, beta-hemolytic group A streptococci, which are factors in the development of angina, but can also be part of the physiological flora.

Rapid tests are available in the doctor's office to check for infection with group A hemolytic streptococcus. A positive result allows you to confirm the diagnosis of an adult and justify the appointment. antibiotic therapy. In children, despite a positive test result, a smear with culture is required.

Bacterial infection and antibiotics

Most bacterial infections, like viral infections, disappear after a few days, even if treated without antibiotics. However, it should be understood that improper treatment of a bacterial infection can lead to a number of complications. Recurrent bacterial infections of the pharynx and palatine tonsils can lead to abscesses. In addition, bacterial infection can spread to adjacent tissues, and even cause a generalized infection in the form of septicemia and sepsis.

It happens that despite antibiotic treatment, the bacterial infection persists. Therefore, it is worth performing a smear before starting antibiotic therapy in order to know which bacteria you have to deal with, and, in addition, antibiogram allows to determine the sensitivity of bacteria to certain antibiotics.

Therapy starts with empirical treatment because culture and antibiogram results will not be available until a few days later. You can then start targeted treatment by changing the medication used if the current one does not bring any therapeutic effect.